Nerys, thats a lovely memory, it seems our parents didn't mind us going off in those days.
When I was 14 my adventures started with me and my best friend going off to the east coast ,usually Mablethorpe or Cleethorpes each weekend during summer months.
We had a tandem each, so we could possibly pick up the girls, and we had a trailer each to carry our camping gear and our kayak. Sometimes we would paddle from Leicester along the river Soar onto the Trent and finally into the Humber, down the coast to Cleethorpes and camp in the dunes, fishing and exploring each day then paddle all the way back, the journey used to take about 20 hours paddling outbound and 35 hours back upstream.
Kids these days wouldn't have a clue, as they are not allowed the freedom we had.